package com.hmdp.config;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {
    //开始时间戳
    private static final long BEGIN_TIMESTAMP=1640995200L;
    //序列号位数
    private static final int COUNT_BITS=32;
    private StringRedisTemplate stringRedisTemplate;
    public RedisIdWorker(StringRedisTemplate stringRedisTemplate){
        this.stringRedisTemplate=stringRedisTemplate;
    }
    public long nextId(String keyprefix){
        LocalDateTime now=LocalDateTime.now();
        //时间戳序列号
        long nowSecond=now.toEpochSecond(ZoneOffset.UTC);
        long timestamp=nowSecond-BEGIN_TIMESTAMP;
        //生成序列号
        //获取当前日期
        String date=now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        //自增长
        long count=stringRedisTemplate.opsForValue().increment("icr:"+keyprefix+":"+date);
        //拼接后返回
        return timestamp<<COUNT_BITS|count;
    }
}
